White fibrous papulosis of the neck

[Atypical eruptive collagenoma: two cases]

BACKGROUND

Eruptive collagenoma is a rare cutaneous lesion seen in young adults. It consists of asymptomatic, flesh-coloured papules that are usually localised on the trunk and the root of the upper limbs. Herein we report two cases on account of the atypical topography of the lesions and the advanced age of the patients.

CASE REPORTS

Case n 1: a 69-year-old man consulted for firm, whitish papules on the wrists, elbows, popliteal fossae and groin without associated signs, and which first appeared several years earlier. The standard laboratory assessment and ocular fundus test were normal. Case no 2: a 69-year-old woman had very firm, flesh-coloured papules on the trunk and the root of the limbs, which appeared after the age of 40. The results of ocular fundus, cardiovascular investigation and laboratory examinations were normal. The histology of papules was similar in both cases and revealed a nodular zone in the reticular dermis, comprising disorganized collagen bundles and excessive quantities of elastic fibres, without elastorrhexis. This histology was consistent with collagenoma.

DISCUSSION

We report two singular cases that were atypical in terms of patient age and localisation in the flexion folds. Histological analysis of a papule enables a diagnosis of collagenoma to be made. Such analysis usually reveals a hamartoma in which the amount of collagen is increased, with variable quantities of elastic tissue, though often decreased. The principal differential diagnoses are elastoma and pseudoxanthoma elasticum.

Pseudoxanthoma elasticum papillary dermal elastolysis: a case report

PXE-PDE is a rare clinicopathological entity with few cases reported. It affects more often elderly women and is characterized by asymptomatic bilateral and symmetrical yellowish papules localized predominantly on the neck and supraclavicular regions. It is clinically similar to Pseudoxanthoma Elasticum. The authors report a case of a 64-year-old woman presenting asymptomatic, yellowish, non-follicular papules, affecting the occipital and the posterior region of the neck for 1 year. The patient denied pruritic or inflammatory changes, marked solar exposition or trauma on the affected areas. Routine laboratory studies: thoracic x-ray and ophthalmologic examination were normal. The histopathologic examination of a biopsy of one of the cutaneous lesions showed an absence of elastic fibers in the papillary dermis.The diagnosis of Pseudoxanthoma Elasticum-like Papillary Dermal Elastolysis (PXE-PDE) was made. Of great importance is the differential diagnosis with Pseudoxanthoma elasticum (PXE), but we have also to consider other elastolytic disorders: mid-dermal elastolysis (MDE), linear focal elastosis (LFE) and white fibrous papulosis of the neck (WFPN). Until know, there is no effective treatment for this pathology.